Chapter 4 - Molecules and Compounds

Question 1

What are the 3 types of chemical bonds?

Answer 1

covalent, ionic, metallic

Question 2

What are covalent bonds?

Answer 2

non metal reacting with non metal
sharing of electrons
lower melting and boiling point

Question 3

What are Ionic bonds?

Answer 3

metal reacting with non metal
transfer of electrons
higher melting point and boiling point

Question 4

What are metallic bonds?

Answer 4

metals bonding together

Question 5

What is the Empirical formula?

Answer 5

relative number of each atom (e.g. CH)

Question 6

What is the molecular formula?

Answer 6

the actual number of each atom (e.g. C6H6) (Benzene)

Question 7

What are Lewis Dot structures?

Answer 7

simple way to depict the valence electrons in an atom, product reactivity and structure of compounds (represented by dots of electrons in outer shells)

Question 8

What is the Octet rule?

Answer 8

atoms tend to gain, lose or share electrons until they have a full outer shell

Question 9

In Ionic bonding which elements lose electrons? to form what?

Answer 9

Alkali and alkaline earth metals due to low ionisation energy
form cations

Question 10

In ionic bonding which elements gain electrons? to form what?

Answer 10

Halogens - have a high electron affinity
form anions

Question 11

What is lattice energy?

Answer 11

stabilisation that accompanies the formation of the crystal lattice
heat released when the solid crystal forms from separate ions in the gas state
always exothermic

Question 12

What can lattice energy be calculated by?

Answer 12

is hard to measure directly, can be calculated by Born-Haber cycle

Question 13

What are the steps to naming a binary ionic compound where metal has only 1 possible charge?

Answer 13

1. full name of cation (metal)
2. add ‘ide’ to anion (non metal)

Question 14

How do you name an ionic compound where metal has multiple charges?

Answer 14

1.full name of cation
2. charge of cation (represented in roman numerals in brackets) (e.g. Pb (IV) … )
3. add ‘ide’ to anion

Question 14

Polyatomic Ions need to be memorised; what is C2H3O2^-

Answer 14

Acetate

Question 15

What is CO3^2-?

Answer 15

Carbonate

Question 16

What is HCO3^-?

Answer 16

Hydrogen carbonate (or bicarbonate)

Question 17

What is OH^-

Answer 17

Hydroxide

Question 18

What is NO2^-

Answer 18

Nitrite

Question 19

What is NO3^-

Answer 19

Nitrate

Question 20

What is CrO4^2-

Answer 20

Chromate

Question 21

What is Cr2O7^2-

Answer 21

Dichromate

Question 22

WHat is PO4^3-

Answer 22

Phosphate

Question 23

What is HPO4^2-

Answer 23

Hydrogen phosphate

Question 24

What is H2PO4^-

Answer 24

Dihydrogen phosphate

Question 25

What is NH4^+

Answer 25

Ammonium

Question 26

What is ClO^-

Answer 26

Hypochlorite

Question 27

WHat is ClO2^-

Answer 27

Chlorite

Question 28

WHat is ClO3^-

Answer 28

Chlorate

Question 29

What is ClO4^-

Answer 29

Perchlorate

Question 30

What is MnO4^-

Answer 30

Permanganate

Question 31

What is SO3^2-

Answer 31

Sulfite

Question 32

What is HSO3^-

Answer 32

Hydrogen sulfite (or bisulfate)

Question 33

What is SO4^2-

Answer 33

Sulfate

Question 34

What is HSO4^-

Answer 34

Hydrogen Sulfate (Bisulfate)

Question 35

What is CN^-

Answer 35

Cyanide

Question 36

What is O2^2-

Answer 36

Peroxide

Question 37

How do you name a polyatomic ion?

Answer 37

1. name of cation
2. name of polyatomic ion

Question 38

What are Hydrates?

Answer 38

water molecules built into ionic lattice